Regeneron Pharmaceuticals, and Sanofi, announced positive results from the interim analysis of a dose-ranging phase 2b study of dupilumab in adult patients with uncontrolled moderate-to-severe asthma.  Dupilumab is an investigational therapy blocking IL-4 and IL-13, two cytokines required for the Th2 immune response.

"Many have thought that targeting the Th2 pathway in asthma would limit benefit to a subset of asthmatics, such as those with high eosinophils.  In this study, blocking IL-4/IL-13 signalling with dupilumab improved lung function and reduced severe exacerbations in the broader study population," said Elias Zerhouni, MD, president, Global R&D, Sanofi.  "Based on these
results, we plan to move dupilumab into phase 3 clinical development in patients with moderate-to-severe uncontrolled asthma."

In the study, the three highest doses of dupilumab in combination with standard-of-care therapy met the primary endpoint of a statistically significant improvement from baseline in forced expiratory volume over one second (FEV1, a standard measure of lung function) at Week 12 in patients with high blood eosinophils (greater than or equal to 300 cells/microliter), as compared to placebo in combination with standard-of-care therapy.  In addition, two doses of dupilumab (200 mg every other week and 300 mg every other week) showed a statistically significant improvement in mean percent change in FEV1, as well as a reduction in severe exacerbations, in both the high eosinophils and overall study population.

In the high eosinophils patient group:Mean improvements from baseline in FEV1 (and mean percent change in FEV1) at 12 weeks, the primary (and a secondary) endpoint of the study were: 390ml (26 per cent) dupilumab 300 mg every other week (Q2W); 430 ml (26 per cent) dupilumab 200 mg Q2W; 180 ml (10 percent) placebo. (p less than 0.01).

In the overall population : Mean improvements from baseline in FEV1 at 12 weeks (and mean percent change in FEV1) were: 280 ml (18 per cent) dupilumab 300 mg Q2W; 310 ml (18 per cent) dupilumab 200 mg Q2W; 120 ml (6 per cent) placebo. (p less than 0.001).

In both the high eosinophils patient group and overall patient group Dupilumab showed a reduction in adjusted annualised rate of severe exacerbations compared to placebo  (64 to 75 per cent reduction, p less than 0.05 for high eosinophils group and p less than 0.01 for the overall population).

These results were based on a pre-specified interim analysis, which occurred when all patients had reached Week 12 of the 24-week treatment period; the average treatment duration at the time of the analysis was 21.5 weeks.  The final analyses onexacerbations and safety will occur at 24 weeks.

The most common adverse event was injection site reaction, which was more frequent in the four dupilumab dose groups (13 to 25 per cent) compared to placebo (12 per cent).  Other common adverse events in the study included upper respiratory tract infection (10 to 13 per cent dupilumab; 13 per cent placebo), headache (5 to 10 per cent dupilumab; 8 per cent placebo),nasopharyngitis (3 to 10 per cent dupilumab; 6 per cent placebo) and bronchitis (5 to 8 per cent dupilumab; 8 per cent placebo).

The incidence of infections was balanced across treatment groups (42 to 45 per cent dupilumab; 46 per cent placebo), as was the incidence of serious adverse events (3 to 7 per cent dupilumab; 5 per cent placebo).

"Patients with moderate-to-severe asthma have a high unmet medical need, often struggling with daily symptoms and recurring asthma attacks, despite the use of inhaled steroids, long-acting beta agonists and rescue medications," said George D.Yancopoulos, M.D, chief scientific officer of Regeneron and president of Regeneron Laboratories.  "This trial is encouraging given the positive results observed on the most clinically meaningful endpoints-FEV1, a key measure of lung function, and asthma exacerbations-were seen on top of ongoing background therapy.  We look forward to continued investigation in further studies."

The double-blind, placebo-controlled, 24-week, dose-ranging study enrolled 776 adult patients with moderate-to severe uncontrolled asthma, as defined by the Global Initiative for Asthma 2014 Guidelines.  Trial participants were randomised to receive one of four doses of dupilumab (300 mg every other week, 200 mg every other week, 300 mg monthly, 200 mg monthly) or placebo. Approximately 40 per cent of patients had high eosinophils across the dose groups.  During the treatment period, patients continue their stable medium-or high-dose inhaled corticosteroid and long-acting beta agonist (ICS/LABA) combination product.  Patients can administer inhaled rescue medication as needed during the study.  A severe exacerbation event during the study is defined as a deterioration of asthma requiring the use of systemic corticosteroids for three or more days, or hospitalisation or an emergency room visit.  Approximately 77 per cent of randomised patients have a history of atopic disease, which includes atopic dermatitis, allergic conjunctivitis, allergic rhinitis, chronic rhinosinusitis, nasal polypsis, food allergy and/or hives history.

The 24-week treatment period of the study is ongoing, and patients will be followed for 16 weeks after treatment.  Full results of the trial will be presented at an upcoming scientific meeting.

About Dupilumab and IL-4/IL-13 Signalling  Dupilumab, a fully-human monoclonal antibody, is directed against the shared IL-4 receptor alpha subunit, which blocks signalling from both IL-4 and IL-13. IL-4 and IL-13 are key cytokines that are required for the initiation and maintenance of the Th2 (Type 2 helper T-cell) immune response, which is believed to be a critical pathway in allergic inflammation.

Dupilumab was created using Regeneron's pioneering VelocImmune technology and is being co-developed with Sanofi in asthma, atopic dermatitis and chronic sinusitis with nasal polyposis.  Dupilumab is an investigational agent under clinical development and its safety and efficacy have not been

Asthma is a chronic inflammatory disease of the airways characterised by airway sensitivity to environmental and biologic factors such as dust, chemicals, smoke, allergens and viral infections leading to an acute and chronic narrowing of the airway and increased mucus production.  Patients with asthma can experience wheezing, shortness of breath, cough and chest tightness, and in severe cases, these symptoms can be life-threatening.  An estimated 10 to 20 per cent of asthmatic patients are less than optimally controlled despite existing therapies.  

Moderate-to-severe asthma can negatively impact the lives of patients and is associated with a high burden to society both in terms of direct costs of medical care and prescription drugs, as well as loss of productivity. It is estimated that approximately 25 million people in the United States are known to have asthma. The worldwide estimates are between 235-300 million people, with 180,000 deaths annually.